Morr was a powerful and loyal Incubus who faithfully served the Dark Eldar Kabal of the Realm Eternal for many generations, upholding the Silent Brotherhood's oaths to the aging Archon Kraillach. An imposing and ruthless warrior, he efficiently carried out his Archon's orders without question. In the late 41st Millennium, Kraillach conspired with Archons Nyos Yllithian of the Kabal of the White Flames and Xelian of the Blades of Desire to overthrow the tyrannical rule of Asdrubael Vect. To achieve their ends, the Realm Eternal aided Nyos' mission to resurrect the infamous El'uriaq, the legendary tyrant ruler of the shadowy-realm of Shaa-Dom. It was Morr who led the operation planned by Archon Yllithian to steal a pure Exodite Eldar to torture, in order to use her soul to bring about the resurrection of El'Uriaq. Following the success of this operation and the resurrection of the long-dead Archon, Morr's master became increasingly paranoid and weak following a battle with Archon Xelian, forcing Morr to assume much of the day-to-day operations of the Kabal. Eventually, the loyal Incubus was forced to turn on his master when he discovered that El'Uriaq had somehow corrupted Kraillach, possessing his body with a Daemon. Striking down the Archon, he freed his master from the Daemon's grasp. Having broken his oaths of the Silent Brotherhood following this act, Morr quickly vanished, pursued by the outcast Harlequin Motley.
- Path of the Renegade (Novel) by Andy Chambers